2166591 has 8 divisors (see below), whose sum is σ = 3301504. Its totient is φ = 1238040.

The previous prime is 2166581. The next prime is 2166601. The reversal of 2166591 is 1956612.

It is an interprime number because it is at equal distance from previous prime (2166581) and next prime (2166601).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2166591 - 2¹⁴ = 2150207 is a prime.

It is a super-2 number, since 2×2166591² = 9388233122562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51565 + ... + 51606.

It is an arithmetic number, because the mean of its divisors is an integer number (412688).

2^2166591 is an apocalyptic number.

2166591 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2166591 is a deficient number, since it is larger than the sum of its proper divisors (1134913).

2166591 is a wasteful number, since it uses less digits than its factorization.

2166591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103181.

The product of its digits is 3240, while the sum is 30.

The square root of 2166591 is about 1471.9344414749. The cubic root of 2166591 is about 129.3974282571.

The spelling of 2166591 in words is "two million, one hundred sixty-six thousand, five hundred ninety-one".